Conventional vehicle transmissions predominantly employ wet clutches to accomplish gear shifting. Transmissions typically include a transmission fluid which is recycled throughout the transmission. Wet clutches generally provide greater heat transfer and temperature control than dry-clutches. Wet clutches also, however, have a lower coefficient of friction than dry-clutches.
Dry-clutches tend to provide higher coefficients of friction than wet clutches. Dry-clutches can provide lower costs and complexity. Still, dry-clutches can have thermal management issues. For example, dry-clutches can reach higher temperatures in repeat vehicle launch events with heavy vehicle load and road grade conditions. Some dry-clutch transmissions are designed to exhaust cooling air from the transmission housing or recycle the air. This can result in energy wasted since other components of the powertrain can benefit from heated transmission air.
One patent publication teaches a system having a closed-loop energy cycle. U.S. Patent Publication No. 2010/0189839 titled “System and Method for the Co-Generation on Fuel Having a Closed-Loop Energy Cycle” teaches the use of heat exchangers that provide heat to a Wankel engine in order to generate electricity. While this publication teaches general energy conservation techniques within a vehicle powertrain it fails to teach conservation of heat energy for intake control in an internal combustion engine.
Therefore, it is desirable to have a powertrain with dry-clutch transmission having heat conservation techniques that can be used to enhance engine performance.